A white Christmas will be a U.S. rarity in 2011; November the globe's 12th warmest

A white Christmas will be a rarity across most of the U.S. this year, as December temperatures have been more typical of November, and very little snow has fallen. Large portions of the eastern half of the country have been more than 4°F above average so far in December, with temperatures averaging 8°F above average over portions of North Dakota.This is quite a switch from the previous two winters, which were both much colder and snowier than average. All three winters featured La Niña conditions in the Eastern Pacific Ocean, so that cannot explain the difference. A key reason for the December warmth this year and the cold and snowy Decembers of 2010 and 2009 is a weather pattern known as the Arctic Oscillation.

Figure 1. Departure of temperature from average over the 30-day period ending on December 22, 2011. Image credit: NOAA/CPC.

Figure 2. Top: snow depth measured in the U.S. on December 22, 2011, after a month with a strong positive phase of the Arctic Oscillation (AO). Bottom: Snow depth measured in the U.S. on December 22, 2010, after a month with a strong negative phase of the Arctic Oscillation (AO). Image credit: NOAA/NOHRSC.

The Arctic Oscillation and its influence on winter weatherThe Arctic Oscillation (AO), and its close cousin, the North Atlantic Oscillation (NAO), are climate patterns in the Northern Hemisphere defined by fluctuations in the difference of sea-level pressure between the Icelandic Low and the Azores High. It is one of oldest known climate oscillations--seafaring Scandinavians described the pattern several centuries ago. Through east-west oscillation motions of the Icelandic Low and the Azores High, the AO and NAO control the strength and direction of westerly winds and storm tracks across the North Atlantic. A large difference in the pressure between Iceland and the Azores (positive AO/NAO) leads to increased westerly winds and mild winter in the U.S. and Western Europe. Positive AO/NAO conditions also cause the Icelandic Low to draw a stronger south-westerly flow of air over eastern North America, preventing Arctic air from plunging southward. In contrast, if the difference in sea-level pressure between Iceland and the Azores is small (negative AO/NAO), westerly winds are suppressed, allowing Arctic air to spill southwards into eastern North America more readily. Negative AO/NAO winters tend to bring cold winters to Europe and the U.S. East Coast, but leads to very warm conditions in the Arctic, since all the cold air spilling out of the Arctic gets replaced by warm air flowing poleward. The winter of 2009 - 2010 had the most extreme negative NAO and AO since record keeping began in 1865; a very extreme AO/NAO also developed during the winter of 2010 - 2011. But this year, the pattern has flipped. The AO has been almost as strong, but in the opposite sense--a positive AO, leading to very warm conditions over the U.S. Unfortunately, the AO is difficult to predict more than a week or two and advance, and we don't understand why the AO can vary so much from winter to winter. The latest predictions from the ECMWF and GFS models show this positive AO pattern continuing for at least the next ten days. Real winter conditions won't arrive in the U.S. until the first week of January, at the earliest. Between now and the end of 2011, the only major winter storm the GFS model expects in the U.S. will be in the Pacific Northwest, on December 30 - 31.

Figure 3. The departure of temperature from average in Centigrade during the November - December - January period during various phases of the Arctic Oscillation (AO). Positive AO conditions lead to warm winters in the U.S., while negative AO conditions lead to cold winters. Image credit: NOAA/CPC.

A warm November for the U.S. In the contiguous U.S., November ranked as the 25th warmest November in the 117-year record. Thirteen states in the Northeast and Upper Midwest recorded a top-ten warmest November, and no states had a top-ten coldest November. Eight states had a top-ten wettest November--Indiana, Ohio, Missouri,Illinois, Kentucky, Tennessee, Arkansas, and Oklahoma. One state had a top-ten driest month, Minnesota. Texas had its 39th driest November on record, keeping 76% of Texas under extreme to exceptional drought as of December 13, according to the U.S. Drought Monitor.

A weak La Niña continuesA borderline weak/moderate La Niña event continues in the equatorial Pacific, where sea surface temperatures were approximately 1.0°C below average during the first half of December. The impacts of a La Niña on U.S. weather are well-defined. It is likely that the drought in the South, especially Texas, will continue, along with above average temperatures. The Northwest can expect cooler than average temperatures, as well as the potential for another winter with a heavy snowpack across the western United States.

Arctic sea ice extent third lowest on recordArctic sea ice extent was at its third lowest on record in November, behind 2006 and 2010, according to the National Snow and Ice Data Center. Sea ice records date back to 1979.

Donations sought for the East Africa famineWeather Underground has partnered with the International Rescue Committee (IRC) to help the Horn of Africa region during the ongoing famine. With the help of the Weather Underground community, we hope to raise $10,000 that will go toward helping the refugees survive the crisis. Weather Underground will match the community's donation dollar-for-dollar up to $10,000 for a total donation of $20,000. Please visit the East Africa famine donation page to help out. Ninety cents of every dollar donated goes directly to the people in need.

Quoting StormTracker2K:Ouch the -10 degree line on the Euro is all the way down to N FL.

So 14 degrees at 5000 feet in early January? Doesn't sound too bad. Welcome, in fact, after this very warm December, where it's been a little to much above normal 22 of this month's 26 days (and 15 of the last 17 in November). FWIW, the 10-day forecasts I'm seeing show just a minor dip in temps for next Tuesday; it'll be interesting to see whether they pick up on what the Euro is seeing.

(It's interesting to note how warm the western half of the country is forecast to be while the east cools off a bit.)

LOL Look at the Nor-Easter the Euro blows up by next Tuesday over New England. This run is showing coastal sections getting heavy rains with 50 to 60 mph and strong winds with blizzard conditions across the interior. Again the Euro has shown this now since last Friday.

Parts of the south could be digging out of snow this time next week as the coldest air thus far is being depicted here on the Euro. Also this could produce severe wx here in FL before the first freeze arrives. It should be noted that the GFS does not show this at all but the Euro has now for days. So my bets are the Euro is on to something here.

The system is likely to move west-northwestwards, intensify into a severe cyclonic storm during next 24 hrs and cross north Tamil Nadu and south Andhra Pradesh coast between Cuddalore and Nellore by Friday morning.

According to satellite imagery, the Dvorak intensity is T2.5. The lowest cloud top temperature is about -77C. Associated broken low/medium clouds with embedded intense to very intense convection seen over Bay of Bengal between 7.5N to 15.0N and 82.0E to 92.0E.

3 minute sustained winds near the center is 40 knots with a central pressure of 994 hPa. The state of the sea is rough to very rough around the system.

The season of climate refugees begins. The refugees are fleeing not the heat, but the cold. The flow of those climate refugees will reverse itself in about 4 months when the cold subsides. Happy Season to those of us who depend on those climate refugees for our livelihood.

He said they would do aerial sweeps of the scene and then send people in on the ground once it was safe.

"We will move as quickly as we can to remediate this in a timely manner, but we will not be putting anybody else at risk," Mr Easthope said.

The freight train derailed just north of Edith Falls River crossing about 5.30am.

The two drivers were eventually rescued after emergency crews' efforts were hampered by bad weather.

THE remnants of Cyclone Grant are now starting to threaten the Territory's east coast.

A Cyclone Watch has just been declared for a developing tropical low from Nhulunbuy to Numbalwar, including Groote Eylandt.

The weather bureau says that at 12:30 pm Ex-Tropical Cyclone Grant was about 95km south of Jabiru and 445km west-southwest of Nhulunbuy - and was moving south southeast at 2km per hour.

It is expected to begin moving towards the east on Wednesday and is likely to move over the Gulf of Carpentaria on Thursday, where it may redevelop into a tropical cyclone.

It is system is expected to move steadily east across the Gulf of Carpentaria towards Queensland on Thursday and Friday.

THE latest update from NT Police Northern Commander David Proctor:

SEVEN people in five cars stranded on a stretch of the Stuart Highway that's cut off by the flooded Edith River to the south, and the Cullen River to the north.

NINE people, including four children, stranded on the roofs of two houses inundated by floodwaters on Edith Farms Rd.

EMERGENCY services going through options to recover those stranded _ but the Katherine helicopter they used to rescue two train drivers has now been grounded due to bad weather.

THE ROAD bridge at Edith River Crossing has reportedly been damaged by carriages from the derailed freight train that were washed away by raging floodwaters. The train tracks have also been badly damaged. Government inspectors will need to inspect the bridge once the spot is accessible.

SEVERAL Top End river crossings flooded overnight could remain closed for nearly two days, authorities warn.

Falling river levels today have revealed severe damage to the Edith River Bridge northbound.

Experts say the new bridge would need repairs before people could cross.

The only hope is now that the southbound bridge which is still under water has no damage and is passable.

The north and southbound bridges at the Cullen River crossing are also still under water.

And the Fergusson River crossing remains flooded.

Police said they would not reopen any crossing until the Edith River is passable.

Katherine is not on flood warning as the system affected is in the Fergusson catchment which feeds into the Daly River. A minor flood warning exists for Gorge Rd.

THE scene of the train derailment just north of Katherine has been described as one of "devastation''.

Katherine MLA Willem Westra van Holthe arrived at the scene about two hours after the derailment and said there was a huge amount of water coursing through.

"The whole scene is quite shocking,'' he said.

"I've lived in the Territory for 27 years and I've never seen anything like it.

"It was quite apparent ... that the train had gone off its rails and a number of containers had floated downstream and lodged up against the road bridge.''

Mr Westra van Holthe said he could not tell if the road bridge had been damaged, but said an engineer could be needed to clear the bridge for safety before reopening it.

He said the damage to the tracks and Stuart Highway was revealed when the water later began dropping.

"There are sheets of bitumen that have lifted and totally gone,'' Mr Westra van Holthe said.

"There's also an enormous amount of damage to the train track itself.''

The freight train, carrying iron ore, derailed just north of Edith Falls River crossing about 5.30am.

PASSENGERS travelling north on the Ghan are stuck in Katherine after a freight train derailed earlier this morning.

Great Southern Rail spokeswoman Jessica Playford confirmed the Ghan, which was travelling with just under 200 guests, was supposed to get into Darwin later tonight.

She says the train is now in the middle of its scheduled break in Katherine, so the guests' timetable hasn't yet been officially disrupted.

Ms Playford says it is hoped they will get the passengers into Darwin by coach tonight.

"Depending on what happens with the track and the roads - hopefully the roads will be open later today,'' she said.

Eyewitnesses at the scene of the iron ore train derailment - just north of Edith Falls River crossing _ say the track has been badly damaged.

There are also reports that some of the train's carriages were washed by the flood waters into the car bridge down stream, and damaged that.

Ms Playford said there were already coaches organised to take the passengers from Katherine to Darwin.

The Ghan is also scheduled to leave Darwin for Adelaide tomorrow morning.

Ms Playford estimates just under 200 are booked for that journey as well.

She said they would do the same thing with those guests, and coach them down to Katherine to get on the Ghan there, as long as the roads were open.

At 3:30 PM CST, Tropical Low, Former Grant (999 hPa) located at 14.0S 133.6E or 95 km south of Jabiru and 445 km west southwest of Nhulunbuy has 10 minute sustained winds of 25 knots with gusts of 45 knots. The low is reported as moving southeast at 4 knots.

Dvorak Intensity:

Ex-tropical Cyclone Grant is slowly moving towards the east and is likely to move over the Gulf of Carpentaria later on Wednesday night or early Thursday, where it may redevelop into a tropical cyclone. The system is expected to move steadily east across the Gulf of Carpentaria during Thursday and Friday.

GALES are not expected in coastal areas within the next 24 hours, however gales may develop later if the cyclone forms close to the coast.

HEAVY RAIN is expected to cause flooding of low lying areas over the Darwin-Daly, Arnhem and Roper-McArthur Districts.

Tides will be HIGHER THAN NORMAL between Milingimbi and Groote Eylandt. Large waves may produce MINOR FLOODING of low-lying coastal areas.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Cyclone Watches/Warnings=======================A Cyclone WATCH is current for a developing tropical low for coastal areas from Nhulunbuy to Port Roper, including Groote Eylandt.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 13:30 PM UTC..

The system is likely to move west-northwestwards, intensify into a severe cyclonic storm during next 24 hrs and cross north Tamil Nadu and south Andhra Pradesh coast between Cuddalore and Nellore by Friday morning.

According to satellite imagery, the Dvorak intensity of the system is T2.5. The lowest cloud top temperature is about -77C. Associated broken low/medium clouds with embedded intense to very intense convection is seen over Bay of Bengal from 7.5N to 15.0N and 82.0E to 90.0E. A buoy observed at 12.4N 85.9E reports surface low pressure of 998 hPa.

3 minute sustained winds near the center is 40 knots with a central pressure of 994 hPa. The state of the sea is rough to very rough around the system center.

At midday WST a tropical low was located near 11S 092E and is moving slowly westward. The low is expected to move west of 090E, outside of the Western Region later on Wednesday. It is not expected to develop into a tropical cyclone while in the Western Region

Quoting wildheron:aren't new years resolutions made to be broken? (any bets on how long gro keeps this one?) hope everyone had a wonderful christmas--have a happy new years! ....back to lurking

Grothar is a really nice guy, never says anything out of the way unless he hasnt slept much lol. as for the resolution of no joking on the blog...Grothar, i will give you till May before you break that xD

At 12:30 PM CST, Tropical Low, Former Grant (1000 hPa) located at 13.5S 132.9E or 95 km south of Jabiru and 445 km west southwest of Nhulunbuy has 10 minute sustained winds of 25 knots with gusts of 45 knots. The low is reported as moving south southeast at 1 knot.

Dvorak Intensity:

Ex-tropical Cyclone Grant is expected to begin moving towards the east during Wednesday and is likely to move over the Gulf of Carpentaria on Thursday, where it may redevelop into a tropical cyclone. The system is expected to move steadily east across the Gulf of Carpentaria during Thursday and Friday.

GALES are not expected in coastal areas within the next 24 hours, however gales may develop later if the cyclone forms close to the coast.

HEAVY RAIN is expected to cause flooding of low lying areas over the Darwin-Daly, Arnhem and Roper-McArthur districts.

Tides will be HIGHER THAN NORMAL between Milingimbi and Groote Eylandt. Large waves may produce MINOR FLOODING of low-lying coastal areas.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Cyclone Watches/Warnings=======================

A Cyclone WATCH has been declared for a developing tropical low for coastal areas from Nhulunbuy to Numbalwar, including Groote Eylandt.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 7:30 AM UTC..

The death toll from flash floods that swept away entire villages in the southern Philippines climbed to nearly 1,500 today, as authorities widened their search for bodies.

The Office of Civil defence's latest tally listed 891 dead in Cagayan de Oro and an additional 451 in nearby Iligan city. The rest came from several other provinces. Most of the dead are unidentified.

"The search will continue as long as we are recovering bodies," said Civil defence head Benito Ramos.

He said that decomposing remains were retrieved floating in the sea as far as 100 kilometers from the two cities where a Dec. 16 tropical storm unleashed more than a month's worth of rainfall in 12 hours, sending walls of water gushing into homes.

It was not clear how many more are missing.

More than 60,000 homeless from hundreds of flood-ravaged villages spent a miserable Christmas in jam-packed schools and gymnasiums, while the United Nations launched an urgent appeal for $28 million to help the displaced more than half the population of Cagayan de Oro and Iligan, which are in the southern Philippines' Mindanao region.

President Benigno Aquino III, who banned logging in February following previous flooding deaths that experts say were caused partly by deforestation and soil erosion, has ordered an investigation.

Communist guerrillas in the south, meanwhile, threatened to punish multinational companies they blame for environmental destruction.

Rebel spokesman Jorge Madlos told The Associated Press by telephone that they sought funds for victims from huge pineapple and banana plantations and other companies.

"Some were lukewarm to our call," Madlos said. "That'll be a factor when we decide which ones to punish first for this destruction."

Another factor in the staggering death toll was illegal settlements along Cagayan rivers. Thousands of people lived in shanties on the banks and islands directly along the water's path.

The system is likely to move west northwestward, intensify into a severe cyclonic storm during the next 24 hours and cross north Tamil Nadu and south Andhra Pradesh coast between Cuddalore and Nellore by Friday morning.

According to satellite imagery, the Dvorak intensity of the system is T2.5. The lowest cloud top temperature is about -85C. Associated broken low/medium clouds with embedded intense to very intense convection seen over Bay of Bengal from 8.0N to 15.0N east of 82.5E, over south Bay of Bengal. The poleward outflow is distinctly visible in the satellite imagery, which favors intensification. Ship observations (11.5N 92.7E) observed surface low pressure of 1007 hPa.

3 minute sustained winds near the center is 35 knots with a central pressure of 994 hPa. The state of the sea is rough to very rough around the center.

Considering the environmental features, the sea surface temperature is about 27-28C over the region. It is relatively less towards Tamil Nadu and Sri Lanka coast becoming 26-27C. The ocean thermal energy is 50-80 kj/cm2 around the system. It is 50-80 kj/cm2 to the west and west northwest of system and less than 50 kj/cm2 near Tamil Nadu and north Sri Lanka. The Madden Jullian Ocillation index currently lies over phase 5. As per statistical and numerical weather prediction model predictions, it is expected to lie in phase 5 during next week. The phase 5 is favorable for intensification, as per our past studies. The upper tropospheric ridge lies along 15.0N and hence provides required poleward outflow for intensification of the system. The low level convergence increased during past 6 hours as well as upper level divergence. The vertical wind shear between 200 and 850 HPA is low to moderate. However, it increases towards the coast of Sri Lanka, becoming 20-30 knots. Wind shear tendency around the system is negative of the order of 10-20 knots.

The next tropical cyclone advisory from India Meteorological Department will be issued at around 6:00 AM UTC..

The water was off to about 250,000 people. It was a mess. We were on a boil water all day yesterday. It wasn't a nice sight.

I have been without water, from a broken main, for a few short hours. I cannot imagine the sense of urgency and helplessness you probably felt when you had 22 guests to care for. What a nightmare that must have been! ... The one time you probably wished you could turn wine into water?

Year is not over yet Grothar. Keeping everything crossed that nothing else happens. Sorry you had to send home your maids and butlers when the water went out X-Mas eve. I just enjoyed my can of Spaghettios and went to bed.

Don't keep everything crossed, Geoff. It could get uncomfortable. Besides, we do not have a butler. We have not had one for years.

Year is not over yet Grothar. Keeping everything crossed that nothing else happens. Sorry you had to send home your maids and butlers when the water went out X-Mas eve. I just enjoyed my can of Spaghettios and went to bed.

The system is likely to move northwestwards, intensify into a severe cyclonic storm during next 24 hrs. Then it is likely to move west-northwestwards and cross north Tamil Nadu and south Andhra Pradesh coast between Cuddalore and Nellore by Friday morning.